Humidity producing devices such as humidifiers and vaporizers provide moist air to a room by atomizing or evaporating water. This may be done to make a room more comfortable and to provide a healthier environment.
Ultrasonic humidifiers are known in the art; one such humidifier is described in U.S. Pat. No. 4,238,425 to Matsuoka, et al. Such humidifiers apply ultrasonic energy to a water supply to atomize the water. The atomized water and water vapor is exhausted from the humidifier as a fog or mist using a fan; the fog or mist evaporates into the surrounding air. Such humidifiers often include a switch or detector which shuts down the operation of the humidifier when the water is used up.
Typically, the output of an ultrasonic humidifier is an exhaust of visible mist. It may be possible to detect when the water in such a humidifier has been consumed and the humidifier has ceased operation by the absence of such a mist. However, since such humidifiers are substantially silent, it may be difficult for a user to detect when the humidifier has ceased operation. Furthermore, it may be possible to make such humidifiers more attractive and more interesting and fun to use.
Therefore, there exists a need for an ultrasonic humidifier which provides an attractive exhaust stream. Furthermore, there exists a need for an ultrasonic humidifier where a user may easily detect when the humidifier has ceased operation.